|Mapa das emissões de enxofre por navios. Reparem o litoral norte e nordeste do Brasil. Fonte: gCaptain|
|Emissões de NOx nas rotas globais de navegação. Fonte: Ship Emissions Assessment|
Aviation and shipping cannot trade away emissions, scientist warnsDavid Adam, environment correspondent
Carbon trading will not solve the problem of soaring emissions from the aviation and shipping industries, a new analysis shows.
Future carbon cuts must be so severe, that both sectors will have to curtail future growth to tackle global warming, according to research presented at a climate change conference at Exeter University today.
Emissions from international aviation and shipping are growing rapidly, but are excluded from existing plans to cut carbon.
Faced with growing pressure to act, experts are working to link them to carbon trading markets, such as the European emissions trading scheme.
This would allow the aviation and shipping industries to buy carbon credits to cover their increased pollution, with the costs passed on.
But Alice Bows, a climate scientist at the Tyndall Centre for Climate Change Research at Manchester University, said future carbon cuts needed to be so severe that both sectors would have to reduce their own emissions as well.
Bows said: "They can't trade their way out of this problem. At current rates of growth, they will be consuming a significant proportion of the world's carbon budget by 2050. It will be way more than their fair share and an amount that simply can't be traded away because everybody else will have been forced to cut emissions."
Scientists say that unless soaring greenhouse gas emissions are curbed immediately, carbon dioxide levels in the atmosphere are on track to pass 650 parts-per-million (ppm), which could bring an average global temperature rise of 4C.
According to the government's Stern review on the economics of climate change in 2006, this would mean that between 7 million and 300 million more people would be affected by coastal flooding each year, there would be a 30-50% reduction in water availability in southern Africa and the Mediterranean, agricultural yields would decline 15-35% in Africa and 20-50% of animal and plant species would face extinction.
Earlier this year, a leaked UN study seen by the Guardian revealed that the true scale of climate change emissions from shipping was almost three times higher than previously believed.
It calculated that annual emissions from the world's merchant fleet had already reached 1.12bn tonnes of CO₂, or nearly 4.5% of all global emissions of the main greenhouse gas.
The report suggested that shipping emissions would become one of the largest single sources of manmade CO₂ after cars, housing, agriculture and industry. By comparison, the aviation industry, which has been under heavy pressure to clean up, is responsible for about 650m tonnes of CO₂emissions a year, just over half that from shipping.
Fonte do texto: The Guardian
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